Electromagnetic bell and vibratory mechanism



Jan. 5, 1932. M D 1,839,342

ELECTROMAGNETIC BELL AND VIBRA'IORY MECHANISM Filed y 1926 5 Sheets-Sheet 1 3 Z f I rr s5 27 28 5 Y 729. I g

I NVEN TOR.

5.024 is Cf. Kit/71710;!

Jan. 5, 1932. M0 1,839,342

. ELECTROMAGNETIC BELL 'AND VIBRATORY MECHANISM Fi M y 192a 5 Sheets-Sheet 2 I. 'IQIIIIII I N VEN TOR.

Soufs (F. Kit/21170116! BY 09 M Y ATTORNEY Jan. 5, 1932. L. E. RICHMOND 1,839,342

ELECTROMAGNETIC BELL AND VIBRA'IORY MECHANISM Filed y 1926 5 Sheets-Sheet s INVENTOR.

40 21156. Kit/211101114X BY (@4 7, 06% h- 1&4? ATTORNE 6 Patented Jan. 5, 1932 PATENT OFFICE LOUIS E. RICHMOND, OF SHELBY,

SHELBY, OHIO,

OHIO, ASS IGNOR TO THE AUTOCALL COMPANY, OF

A CORPORATION OF OHIO ELECTROMAGNETIC BELL AND VIBRA'I'ORY MECHANISM Application filed Kay 17,

This invention as indicated relates to an electro-magnetic bell and vibratory mechanism. More specifically it may be embodied in an electromagnetic apparatus of the solenoid type adapted particularly for use with an alternating current. It also includes a mechanism wherein, with a single standard form of solenoid coil and energizing means, the characteristics of the plunger employed determine whether the apparatus will function as a single impulse or vibratory mechanism. The device is particularly applicable to alternating current bells but it is not intended to limit the use of the invention to such specific mechanism as certain of the fea tures thereof are of broad application and are based on the operation of a mechanism, at a period bearing a definite ratio to the impulses of an alternating current, through mechanical and electromagnetic influences.

The invention will be described in connection with an electromagnetic bell but such devices have extremely and involve relatively high manufacturing scription is merely intended to be illustrative and not in any sense restrictive.

Alternating current bells, as heretofore constructed, have been single stroke bells, or Where repeated or vibratory action was in view, have involved the use of a retracting spring to cause the plunger to reciprocate out of step with the successive alternations or have involved the use of double coils and a current interrupter to reduce the number of reciprocations to the desired point. Such delow electrical efliciency expense.

In no instance heretofore, so far as is known, has a bell unit been produced capable of serving as either a single stroke or vibratory signal, through the mere substitution of a plunger in a solenoid coil, the other parts of the mechanism remaining unchanged. lhe term vibratory as used in this specification, is intended to apply to the repeated reciprocations of a solenoid plunger as contrasted with a single movement of a plunger normally produced through the energization of a solenoid coil by means of an alternating current.

While bell mechanism operated by alternating current has a wide field of possible 1926. Serial No. 109,707.

use, and is highly desirable from the standpoint of simplicity of'construction, "suitability for series installation, and for direct operation on standard alternating currentpower lines, and has been recognized as of particular value in places where direct current mechanism, with the usual circuitbreaker, would involve fire or explosion risks, the low power factor heretofore present in such alternating current apparatus has prevented its general introduction.

The principal object of the present invention is to avoid the disadvantages referred to and to provide a bell adapted to operate eflectively on alternating current. Another object of the invention is to provide a bell convertible to either single stroke or vibratory action through the substitutioii'pf a suitable plunger and without other change in the apparatus. Another object of theinvention is to provide a vibratory mechanism capable of satisfactory operation on alternating current lines of various voltages and which will operate uniformly irrespective of the angular position of the plunger, except that when the single stroke plunger is used, the position must be such that gravity will readily retract the plunger from the gong. A further object of the invention is to provide a simplified bell mechanism wherein a minimum number of parts is employed and greater efficiency and durability of construction is provided for. A still further object of the invention is to provide an improved housing for the bell mechanism and improved structural elements for such mechanisnr. Other and further objects of the invention will appear in the course of the following description. To the accomplishment of the foregoing and related ends, said invention, then consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawings and the following description set forth in detail certain mechretaining sleeve,

- sition is required Fig. 1 is a central vertical sectional view showing a bell unit embodying the princiles of the invention, the vibratory plunger ing shown in place, and the parts being shown actual size; Fig. 2 is a vertical se tional view showing a single stroke plunger adapted for use with the mechanism shown in Fi 1, said plunger being shown actual size; Fig. 3 is a transverse sectional view taken along'the line 3-3 shown in Fig. 1, looking in the direction of the arrows; Fig. 4 is a detail "iew, partly in section, taken along the line 44 shown in Fig. 1 looking 1.- the direction of the arrows; Fig. 5 is a sectionaldetail view taken along the line 5-5 shown in Fi 4 looking in the direction of the arrows; Fig. 6 is a view of the plunger shown in enlarged perspective; Fi 7 is a front elevation showing a gong and supporting casing; elevation showing the casing and large sized gong supported thereon; Fig. 9 is an inside view of the coversection of the casing; Fig. 10 is a top plan view of the bottom section of the casing with the electromagnetic apparatus installed therein; and Fig. 11 is a view partially in section, taken along the line 1111 shown in Fig. 10, looking in the direction of the arrows, and illustrating the plunger latch mechanism. As is learly shown in Fig. 1 of the drawings, the apparatus comprises a casing 1, on which is supported a bell or sounding element 2, and within which is housed an electromagiietic device 3 for moving a plunger genera y designated as 4 to bring the head of the same into sharp impact with said bell. e casing includes a base section 5 in the form of a box open at its front and having suitable knock-outs 6 at spaced points about its side and back walls 7, 8, to permit the introduction of connecting cables from whichever direction will be found most convenient. The casin will be described as being adapted to e positioned vertically, the plunger operatlng in an upward direction, but it is to be understood that when the vibratory plunger is used, equally satisfactory operation may be obtained from the apparatus with the plunger disposed downwardly, or horizontally, or at any intermediate angular position. With the single stroke plunger, however, a substantially vertical pofor satisfactory operation. The base section of the casing is provided adjacent its upper edge with a hinge member 9 in the form of a lug from each side of which pivot pins 11 project. At the opposite end an enlargement 12 is provided through which a securing screw 13 is threadedly engaged. On the inner side of the top wall of the base section of the casing adjacent one side thereof, a stud 41, is provided, upon which a latch member 42 is pivotally engaged. Said latch member is adapted to Fig. 8 is a side be held in angular position with its free end across the upper end of the tubular core of the solenoid or in contact with the vibratory plunger positioned therein by means of a coiled spring 43 mounted upon said stud. The opposite end of said coiled spring is engaged against a companion stud 44 which also-serves as a stop to limit the upward movement of thelatch. The latch is adapted to be retracted by means of a latch retracting lug formed on the cover as will be presently described.

The cover section 14 of the casing is provided with a pair of slotted lugs 15 opening upwardly and positioned in spaced relation to each other, said lugs being adapted to engage over the pivot pins heretofore described and form a hinge in cooperation therewith.

The cover plate on its inner face is provided with a rib 16 spaced from the margin thereof and adapted to fit closely within the side walls of the base section. Adjacent one side, a latch retracting lug 17 is provided for the purpose of pressing rearwardly the plunger latch 42 heretofore described to permit the free action of the plunger when the cover is in place. At the lower end of the inner face of the cover, a projecting lug 18 is provided, said lug having a conical recess 19 in its outer face to receive and center the end of the retaining screw 13, carried in the enlargement on the base section of the casing, When the latter is turned to locking position.

The cover section of the casing is of substantially plate-like form, but is provided centrally with an outwardly bowed section 21 adapted to accommodate the projecting portion of the electromagnetic device. An aperture 22 formed through the end Wall of said outwardly-bowed section provides for the free movement of the plunger into contact with the gong. The outwardly-bowed central portion of the coverplate tapers toward the end, as is clearly shown in Fig. 9 of the drawings, and merges with a central upstanding rib 23. The rib is formed with a flat upper surface and is made of greater thickness than the balance of the cover section of the casing. At spaced points the rib is provided with a series of threaded apertures 24 into which the threaded ends of the fastening screws 25 are adapted to engage. The upper edge of the cover plate is preferably provided with an integral arcuate-shaped projecting portion or flange 26 which extends downwardly to form a weather-shield for the gong.

The bell member, or gong, 2 is supported centrally upon a stud 27 by means of a cap screw 28 engaged in a screw-threaded socket in the end of said stud. The stud has an integral extension plate 29 at right angles at its base through which a plurality of openings 31 are provided, through which the fastening screws 25 are adapted to freely pass. The heads of said screws will rest firmly insulating material,

agpinst the outer face of the extension plate w en the screws are firmly seated in the appropriate apertures in the rib of the cover section of the casing. It will be obvious that by shifting the gong supporting member, or-

turning it so that its extension will be positioned in an opposite direction, the position of the stud will be varied to suitably center a number of difierent sizes of gongs.

The construction of the electromagnetic device and its associated elements will now be described. Said mechanism is mounted upon a air of inclined lugs 32 provided centrally 0 the base or back wall 8 of the casing. Each of said lugs is provided with a screwthreaded aperture 33 and said apertures are engaged by lon fastenin screws 34 which are adapted to rmly hol against said lugs a supporting block 35 of insulating material. Said block is provided with asemi-circular transverse recess centrally of its upper side of a size to receive a tubular member 36 of such as hard rubber, phenolic condensation product, or the like, upon the one end of which the solenoid coil is wound. Said tubular member, which forms a. guideway for the solenoid plunger, is firmly held in the recess of said block by means of a clamping plate 37 of semi-circular crosssection provided with extension wings 38 each apertured to permit the respective securing screws 34 to pass therethrough. The securing screws thus serve to clamp the tubular central member of the solenoid coil firmly against the insulating block and at the same time to hold said block securely to the inclined lugs on the base of the lower section of the casing.

The insulating block is provided adjacent each end with ofi-set shoulders 41 having recesses Within which terminal members 42 for the wire of the solenoid coil are adapted to be seated. Said members comprise angle lates of conducting material such as brass aving bindin screws engaged through the upper horizontal portion which terminates in a wire guiding flange and having downwardly extending portions adapted to be engaged by means of screws extending transversely through the insulating block and having the ends of the solenoid coil engaged beneath the same.

- as is clearly shown in Fig.

The clamping plate for the central tubular member for the solenoid coil is formed integrally with the plunger receiving sleeve 39 6 of the drawings. Said receiving sleeve is provided with an apertured base 45 against which an annular cushion 46 may be seated to serve as a buffer. A slot 47 is provided on the under side of said sleeve to ermit the walls thereof to be slightly sprea to receive the lower end of the centraltubular member of the solenoid coil. A

pair of insulating discs 48 are secured upon the tubular member in spaced relation upon its upper end and the windin 49 of the solenoid is positioned between the same in the usual manner. It has been found that for a coil adapted to operate on a (SO-cycle alternating current of 110 volts, the winding may be of N 31 wire forming a coil having 7,000 turns. Such coil with a vibratory p unger, of a type hereinafter described, will produce reciprocations at the rate of approximately 3,600 strokes per minute which will produce a very satisfactory signal. The ends of the coil are brought beneath the heads of the screws 50 connected to the terminal elements 42 on the supporting blocks as heretofore mentioned, and the ends of the conductor cables from the current source may be secured beneath the binding screws 40 at the respec: tive sides of said supportin block.

As has been heretofore in icated, the solenoid coil is adapted to actuate two distinct types of plungers. The plungers are each formed of suitable material such as soft iron of desired texture. When a single stroke action of the device is desired, a plunger 51 of the shape illustrated in Fig.2 is employed. Said plunger comprises a tubular member open on its under side and preferably closed at its upper end with a cap 52 of bronze of suitable hardness to serve as a contacting member for striking the gong. The cap is of slightly less diameter than the body of the plunger and is firmly secured to the upper end of the tubular body member in an preferred manner. With the tubular mem er 36 open at its under side, and with a bottom opening in the support ng sleeve 39, air suction therein will be reduced as the plunger moves through the central member of the solenoid.

When vibratory action of the hell is desired, it is necessary to use, in the place of the plunger just described,.a plunger of special construction including a movable sleeve or governor section. A plunger of this type is shown in Fig. 1, and is shown the full size of an apparatus which has been success- -minating in a bronze striking member 55.

A sleeve or governor member 56 of slightly more than half the length of thelower member and of equal diameter thereto is engaged over the extension stem. The sleeve, as is clearly shown in Fig. 1 of the drawings, is closed at its upper end by a cap 57 which is centrally apertured to slidingly engage the stem. The body portion of said sleeve is spaced from said stem and forms a housing for a coiled spring 58. The spring is preferably formed of phosphor bronze Wire and is of a length slightly greater than the depth of the housing within said sleeve, thus normally spacing the lower end of the sleeve from the upper face of the plunger, a distance of approximately three thirty-seconds of an inch. The striking head on the vibratory plunger is norma ly spaced approximately one-eighth of an inch from the inner face of the gong. When -the solenoid coil is energized, the striking member or head 55 is drawn into contact with the bell. The sleeve 56 at such time is firmly held by the magnetic lines of force in close contact with the upper end of the lower section 53 of the plunger, the spring being compressed proportionately.

If direct current is used in the solenoid coil, when the circuit is broken, the bell will be struck sharply after the manner of a single stroke plunger. If a master vibrator is placed in the direct current line, a series of strokes will be delivered to the gong as will be well understood.

If the solenoid coil is energized by means of an alternating current, the vibratory plunger will be caused to reciprocate at a rate of one-h alf the number of current impulses on a 60-cycle line. The movement of the parts takes place very rapidly and the relative po sition of the plunger and the governor sleeve and spring and the electromagnetic changes taking place in each of the moving parts cannot be exactly stated. It has been demonstrated, however, that with an apparatus constructed as is shown in Fig. 1, through the interaction of the mechanical and electromagnetic forces described, the plunger will reciprocate at a rate of one-half the number of impulses in the (SO-cycle, 110 volt alternating current and will tap the bell sharply and Without in any way damping the vibrations. The plunger moves at a rate coinciding with every second impulse of the alternating current and is unaffected by its operative position, whether vertical, horizontal or at an intermediate angle. Although the movement of the striking head is only one-eighth of an inch, the vibratory plunger strikes a heavier blow upon the gong than that struck by the single stroke plunger which moves approximately a distance of two inches. An apparatus constructed as shown in Fig. 1, will also operate on a 220 volt, 60-cycle alternating current at the same rate but will deliver a more powerful blow upon the gong, and because of severe wear on the parts it is desirable to confine the operation of the apparatus described to a current of 110 volts. It is obvious that by changing the weight and relative size of the parts of the vibratory plunger its action may be modified and its rate of reciprocation changed, and where the apparatus is to be applied to a use other than bell operation, such changes may be of primary importance. The principle of the operation of the apparatus will be the same, however, whether the mechanism is used for bells, industrial tools, striking mechanism of musical instruments, or a wide range of other a plications for which it may be found to e particularly adapted.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of'the following claims or the equivalent of such stated means he em loye'd.

therefore particularly point out and distinctly claim as my invention:

1. An electromagnetic device comprising a solenoid coil, a freely movable plunger slidably engaged therein, and means slidably associated with said plunger adapted to cause a rebound action thereof with a change in direction of the current in said coil.

2. An electromagnetic device, having in combination a solenoid coil, a freely movable plunger slidably engaged therein, an extension stem on said plunger, a magnetic sleeve slidably engaged on said stem between said plunger and the end of said stem, and resillent means for normally spacing said sleeve from said plunger.

3. An electromagnetic device, having in combination a solenoid coil, a freely movable plunger slidably engaged therein, an extension stem on said plunger, a magnetic sleeve slidably engaged on said stem between said plunger and the end of said stem, and a coiled spring interposed between said sleeve and said plunger.

4. An electromagnetic device, having in combination a solenoid coil, a freely movable plunger slidably engaged therein, an extension stem on said plunger terminating in a head member, a magnetic sleeve slidably engaged on said stem between said plunger and said head member, and a coiled spring interposed between said magnetic sleeve and said plunger, at least a part of said spring being housed within the sleeve.

5. An electromagnetic device, having in combination a solenoid coil, a freely movable plunger slidably engaged therein, an extension stem on said plunger terminating in a head member, a magnetic sleeve slidably engaged on said stem between said plunger and said head member, and a coiled spring interposed between said sleeve and said plunger, at least a part of said spring being housed within the sleeve, and normally spacing the same from each other, and said plunger and magnetic sleeve being adapted to be drawn together under the influence of said coil.

6. An electromagnetic device, having in combination a solenoid coil, a freely movable plunger slidably engaged therein, an extension stem on said plunger terminating in a head member, a magnetic sleeve slidably engaged on said stem between said plunger and said head member, and a coiled s ring interposed between said sleeve and sai plunger,

at least a part of said spring being housed within said sleeve.

7 An apparatus of the character described, having in combination a casing comprising 5 a base section and a cover section, a bell mounted on said cover section, a solenoid coil angularly supported within said base section and projecting beyond the same, said cover section being adapted to form a closure for 10 said base section and a housing for said pro-- jecting portion of said coil, a plunger Within said coil, an opening through said cover section permitting said plunger to move toward said bell, and means for detachably securing said cover section to said base.

8. An apparatus of the character described, having in combination a casing comprising a base and cover section, a solenoid coil adapted to be housed within said sections, a plunger adapted to be freely disposed within said solenoid coil, means associated with said base to prevent said plunger from moving away from said coil and means associated with said cover for releasing said plunger retaining means.

9. An apparatus of the character described, having in combination a casing comprising a base, and a cover section, a solenoid coil mounted in said base, a plunger adapted to be freely disposed within said solenoid coil, a latch pivoted in said base, a spring urging said latch into position to retain said plunger in said coil, and means on said cover for moving said latch out of plunger-retaining position when said parts are assembled.

10. An apparatus of the character described, having in combination a support, an insulating block secured to said support, a lunger receiving sleeve secured to said in- 40 sulating block and formed at its forward end as a clamping member, a non-magnetic tube secured between said insulating block and said clamping member, a solenoid coil wound upon said tube adjacent said insulating block, a freely movable plunger received within said tube and conductors through which said coil may be energized associated with said insulating block.

Signed by me this 26th day of April, 1926. LOUIS E. RICHMOND. 

